Due to their excellent strength, rigidity, and damping properties, as well as low weight, carbon fiber reinforced composites (CFRCs) are being widely used for load bearing structures. On the other hand, with an increased demand and usage of CFRCs, effective methods to re-use waste carbon fiber (CF) materials, which are recoverable either from process scraps or from end-of-life components, are attracting increased attention. In this paper, hybrid yarns consisting of waste staple CF (40 and 60 mm) and polyamide 6 staple fibers (60 mm) are manufactured on a DREF-3000 friction spinning machine with various process parameters, such as spinning drum speed, suction air pressure, and core–sheath ratio. The relationship between different textile physical properties of the hybrid yarns, such as tensile strength, elongation, and evenness with different spinning parameters, core–sheath ratio, and input CF length is revealed.

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The discovery of ferroelectricity in hafnium oxide has revived the interest in ferroelectric memories as a viable option for low power non-volatile memories. However, due to the high coercive field of ferroelectric hafnium oxide, instabilities in the field cycling process are commonly observed and explained by the defect movement, defect generation and field induced phase transitions. In this work, the optical and transport experiments are combined with ab-initio simulations and transport modeling to validate that the defects which act as charge traps in ferroelectric active layers are oxygen vacancies. A new oxygen vacancy generation leads to a fast growth of leakage currents and a consequent degradation of the ferroelectric response in Hf₀.₅Zr₀.₅O₂ films. Two possible pathways of the Hf₀.₅Zr₀.₅O₂ ferroelectric property degradation are discussed.

Many textile products are using materials with higher thickness like foams, spacer fabrics and nonwoven materials in order to provide comfortable softness of the contact surface to the body. Such materials are often joint to another external layer who have to provide optical and mechanical stability of the system, and are joined together into a 3-dimensional geometry. This paper analyses some steps of joining such materials by sewing. The forces in the sewing threads are analyzed analytically. A numerical model based on finite element method (FEM) is implemented in LS-Dyna and the process of compaction of the sewing line, based on the thread force is simulated. The thread force propagation is numerically analyzed in the time, at different friction coefficients and for different foam stiffness. All simulations demonstrate logical results and can be used as a fundament for more complex investigations and optimizations of such products.

Within the SR Dorado-project, which started in July 2022, a sounding rocket and its corresponding ground support equipment and test facilities are being developed and manufactured. This work is done mainly by undergraduate students at Technische Universität Dresden in cooperation with STAR Dresden, the student Space Flight Working Group in Dresden. The rocket will utilize liquid oxygen (LOX) and ethanol as propellants and is currently in its development phase. The current development status of the rocket and its support systems is described. Details on specific subsystems like propulsion system, rocket structure, recovery and telemetry system are presented. This detailed system assessment is supplemented with insights into the test bench and ground support equipment design, which are needed for successfully testing engine and propulsion system as well as conducting the launch campaign. The planned launch is currently set for 2025 and will take place at ESRANGE in Kiruna, Sweden.:1 Introduction 2 The rocket 2.1 Recovery system 2.2 Flight computer(s) 2.2.1 PoC Flightmaster 2000 2.2.2 Altus Metrum TeleMega 2.3 Structure 2.3.1 Main airframe 2.3.2 Aerodynamics 2.4 Propulsion system 2.4.1 Rocket engine 2.4.2 Propellant feed system 2.4.3 Pyro valves 3 Ground support equipment 4 Test bench 5 Summary and outlook Acknowledgements References

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Für die Handhabung von Textilien mit unterschiedlichen Greifern sind diverse Parameter entscheidend wie Luftdurchlässigkeit, Biegesteifigkeit, Querkompression, Elastizität, Feuchtigkeitsaufnahme usw. Die Simulation von Handhabungsprozessen ist mit Hilfe von mechanischen, termischen, strömungs- oder multiphysikalischen FEM-Verfahren möglich. Diese erfordern jedoch eine vollständige Materialcharakteristik. Diese Arbeit zeigt eine systematisierte Analyse der Daten und einige Probleme bei der klaren Definition und reproduzierbaren Ermittlung, die aus der Biegeweichheit, unklaren Querschnitten der Textilien und einer großen Anzahl frei abstehender Faserende auf der Produktoberfläche resultieren. / For the handling of cloth with different grippers, parameters like air permeability, compressibility, elasticity, moisture absorption, etc. The simulation of handling processes is possible with the aid of mechanical, thermal, flow or multiphysical FEM methods. However, these require complete material characteristics. This work shows a systematised analysis of the data and some problems in the clear definition and reproducible determination resulting from the bending softness, unclear cross-sections of the textiles and a large number of freely protruding fibre ends on the product surface.

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One of the visual modification of wood is the formation of dark zone lines (ZLs) via interaction of fungi. The result is called spalted wood, which has hitherto been produced mainly in small batches. The main goal of the present study is to further develop techniques for rapid formation of ZLs in hardwoods. Various white rot and brown rot fungi were tested to this purpose. Initially, interactions of 148 combinations of 17 basidiomycetes in malt extract agar were evaluated and their antagonistic interactions were characterised in order to identify fungal pairs capable of rapidly forming high-quality ZLs. Six types of interactions were observed, among others; antibiosis and inhibition in contact, which differ in terms of variables including mycelial overgrowth and zone line formation. Furthermore, 23 pairs of ZL forming fungi on malt extract agar were identified. Then the interactions of five selected pairs of fungi grown on the hardwood species Acer pseudoplatanus L., Betula pendula Roth. and Populus nigra L. were examined to assess their utility for controlled mycological wood modification, also in terms of a possible substrate dependency of their interactions. The results indicate that Lentinus tigrinus fungus is one of the best and quickest producer of ZLs in mycological wood modification.